Determining the orientation of objects in space

A method and system determines object orientation using a light source to create a shadow line extending from the light source. A camera captures an image including the shadow line on an object surface. An orientation module determines the surface orientation from the shadow line. In some examples a transparency imperfection in a window through which a camera receives light can be detected and a message sent to a user as to the presence of a light-blocking or light-distorting substance or particle. A system can control illumination while imaging an object in space using a light source mounted to a support structure so a camera captures an image of the illuminated object. Direct illumination of the camera by light from the light source can be prevented such as by blocking the light or using a light-transmissive window adjacent the camera to reject light transmitted directly from the light source.